We found that who you are matters with regard to antidepressant use in the United States. Nationally, black Americans with depressive or anxiety disorders were one-third less likely as white Americans to have used antidepressants. Psychiatric need (i.e., symptom severity) was associated with more antidepressant use for whites, but not for black Americans. Antidepressant use was also associated with medical conditions related to vascular disease; however, these associations were independent of coexisting psychiatric conditions. Finally, we found evidence that many antidepressants may be used for maintenance pharmacotherapy of past depressive and anxiety disorders.
The racial differences in antidepressant use we found are much larger compared to previous reports, and we suggest these possible explanations (5
). First, respondents were selected into the NSAL and NCS-R regardless of medical care access, compared to clinic-based or administrative data that are often restricted to populations that have used medical care services. This has particular importance for ethnic minorities. Non-elderly blacks (21%) are nearly twice as likely as whites (13%) to lack health insurance and other factors that enable access to care, and thus would likely be excluded from administrative and clinic-based studies (43
). In this study, insurance coverage was only modestly associated with antidepressant use. Nevertheless, systematically excluding a large portion of uninsured individuals could introduce selection bias that could inflate treatment rate estimates. Second, attempts to explain the comparatively lower use of mental health services by black Americans have focused on racial differences in preferences for social support or alternative treatments (44
). While these hypotheses are plausible, other explanations should be considered (13
). For example, most Americans receive mental health treatment in busy primary care settings where recognition and treatment of depressive and anxiety disorders can be difficult, particularly for black patients (47
). Physicians providing care for black Americans report being less well-trained and having less access to important clinical resources and specialists than those who treat white Americans (48
). The finding that depression severity was related to antidepressant use for whites but not blacks is consistent with the hypothesis that the quality of mental health care available to black Americans is inferior. The large differences in antidepressant use suggest unmet need that may stem from substandard and unaffordable health care encountered by blacks (49
). Attitude and preference differences for antidepressants between blacks and whites may also explain the present findings. Research suggests antidepressant treatment is less acceptable to blacks compared to whites (45
). For instance, Givens and colleagues found that blacks are more likely to prefer counseling to taking antidepressants (51
). Additional work is needed to determine the degree to which differences between blacks and whites in antidepressant use found in this study results from unmet need, differences in attitudes and preference for treatment or some combination of these and other factors.
Psychiatric need increased the odds of antidepressant use, but so did the presence of common medical conditions associated with vascular disease. Medical “need” in the form of risk factors for vascular disease also predicted antidepressant use in this study. Mental disorders are associated with medical conditions, particularly vascular disease; however, the causal nature of the associations is not fully clear. As previously suggested, vascular disorders may be directly associated with the etiology of some forms of depressive conditions (52
). Furthermore, medical conditions symptoms may mimic clinical depression that could lead to antidepressant use. Medical illnesses represent acute stressors that may tip the balance for some individuals and their families toward mental disorder symptomology that may elicit antidepressant use. Alternatively, it is possible that persons with medical conditions have more contact with health care providers, increasing the likelihood their depressive symptoms will be detected and treated. It is clear from our findings that the medical conditions we examined were independently associated with antidepressant use.
Consistent with previous studies, we found that 12-month mental disorders accounted for only about half of antidepressant use (16
). Lifetime depressive and anxiety disorders accounted for a substantial portion of the antidepressant use by individuals not meeting criteria for 12-month disorders. Our findings may reflect the growing awareness and practice by clinicians that psychiatric need may extend beyond the acute phase of these chronic conditions. It remains to be determined if the benefits and potential harm of maintenance pharmacotherapy represent sound preventative clinical practice or overuse.
Together, 12-month and lifetime depressive and anxiety disorders and medical conditions, accounted for 83.3% of all antidepressant use in the U.S. by blacks and whites. This indicates that about one-fifth of antidepressant use may be for other reasons (e.g., smoking cessation). Mental health cost estimates based solely on antidepressant prescriptions without considering other clinical indications could potentially inflate estimates by as much as 20%. The reasons for antidepressant use among those not meeting criteria for depressive and anxiety disorders requires additional investigation.
This study used sophisticated sampling procedures that make it the largest and most inclusive study of antidepressant use among black and white Americans. Although the present results are most likely the best estimates to date, the results of this study should be interpreted in the context of several limitations. First, the NSAL and NCS-R excluded homeless or institutionalized persons, which could underestimate the unmet need for treatment of depressive and anxiety disorders. Second, systematic survey non-response or selection bias could have had untoward effects on our national estimates (18
). Third, as a diagnostic instrument, the WMH-CIDI has a modest sensitivity and high specificity for detecting “true” psychiatric disorders (e.g., major depression) among NSAL and NCS-R respondents (13
). Thus, it is likely that some cases with “true” psychiatric disorders were missed, which could inflate the proportion of respondents without mental disorders using antidepressants. Fourth, research indicates that self-reports of mental health service use often overestimate actual use (54
). Because self-reported use of antidepressants was corroborated with pill-bottle inventories, this potential bias was minimized. Fifth, the medication questions in the NSAL appeared immediately before a section of the interview on the use of mental health services; whereas, the same questions appeared after the same section in the NCS-R. This may have increased antidepressant reporting among blacks while “attenuating” reporting by whites. If such bias was introduced into this comparative study, we may have underestimated the black-white differences in antidepressant use by increasing the estimates for blacks and lowering the estimates for whites. Additionally, other FDA approved indications for antidepressant (e.g., obsessive-compulsive disorder and eating disorders) were not considered in this study which could account for some of the antidepressant use among respondents not meeting criteria for depression or anxiety disorders. Finally, psychosocial treatments were not considered in this report, but are needed to estimate unmet mental health need. On the other hand, antidepressants are by far the most common form of therapy for depressive and anxiety disorders (2
). Given the magnitude of unmet need that we observed, the main inferences of our work would be unlikely to change dramatically had we included psychosocial treatments.
Our findings suggest several directions for future research and policy to improve delivery of mental health care for black and white Americans. First, increased availability and initiation of mental health treatment will require new outreach efforts to underserved patients and clinicians who serve those patients. Second, improving mental health care at common points of service delivery (e.g., primary care) may be needed. Collaborative care models show promise for improving care among diverse populations, patient outcomes and clinician satisfaction, while containing costs (55
). Finally, new independent research to explore the potential value of antidepressant treatment for medical conditions other than the primary indications of depressive and anxiety disorders may be needed.